公开(公告)号：US5072235A

公开(公告)日：1991-12-10

申请号：US543497

申请日：1990-06-26

申请人： John H. Slowik ,  Stephen F. Pond

发明人： John H. Slowik ,  Stephen F. Pond

IPC分类号： B41J2/125 ,  B41J2/01 ,  B41J2/19 ,  G01N27/06

CPC分类号： B41J2/19

摘要： A detection circuit for detecting the existence of non-collapsing bubbles in the ink cells of a thermal inkjet printhead is connected to a heater element of an ink containing cell. The detection circuit has a sensing element of low resistance when compared to the resistance of the heater element so that printing and detecting operations can proceed simultaneously. Current in the heater element is proportional to the potential drop across the sensing element. An amplifier is used to measure the potential drop and is connected to a blocking capacitor. Non-collapsing bubbles are detected if the voltage drop across the sensing element varies from a reference level.

摘要翻译： 用于检测热喷墨打印头的墨盒中非塌陷气泡的存在的检测电路连接到墨水容纳单元的加热元件。 检测电路具有与加热器元件的电阻相比低电阻的感测元件，使得打印和检测操作可以同时进行。 加热器元件中的电流与感测元件上的电位降成正比。 放大器用于测量电位降，并连接到阻塞电容。 如果感测元件两端的电压降从基准电平变化，则检测到非塌陷气泡。

公开(公告)号：US5682184A

公开(公告)日：1997-10-28

申请号：US574089

申请日：1995-12-18

申请人： Joseph F. Stephany ,  Gary A. Kneezel ,  John H. Slowik

发明人： Joseph F. Stephany ,  Gary A. Kneezel ,  John H. Slowik

IPC分类号： B41J2/125 ,  B41J2/175 ,  G01F23/26 ,  B41J2/195 ,  G01F23/00

CPC分类号： G01F23/268 ,  B41J2/17566 ,  G01F23/266

摘要： A capacitor is created in an ink tank supplying ink to an ink jet printhead by placing parallel capacitive plates on sides of the tank with the ink therebetween acting as the capacitor dielectric. An electrical AC potential is applied across the capacitor. Changes in current flow through the plates are detected in a phase sensitive bridge circuit and digital signals are generated and sent to a processor for conversion into low ink level signals. The output signal is also used to identify a particular type of ink by either comparing points on a characteristic curve of the ink volume verses capacitance or, in a second embodiment, by periodically sweeping an applied oscillator voltage over a selected frequency range and comparing measured electrical resonance parameters for the ink tank capacitor with stored information about resonance parameters for different types of ink.

摘要翻译： 在墨罐中产生电容器，通过在墨水两侧放置平行的电容板，墨水在其间用作电容器电介质，从而向喷墨打印头供墨。 在电容器两端施加电气电位。 在相敏电桥电路中检测到电流流过板的变化，并产生数字信号并将其发送到处理器以转换为低油位信号。 输出信号还用于通过比较油墨体积与电容的特性曲线上的点来识别特定类型的墨水，或者在第二实施例中，通过周期性地扫描所选频率范围上施加的振荡器电压，并比较测量的电 具有储存的关于不同类型墨水的共振参数的信息的墨槽电容器的共振参数。